https://securitylessons.com/guides/ Cisco security explained by a practicing CCIE (#59770, Enterprise Infrastructure and Security) - firewalls, identity, zero trust, AI and quantum-safe security. en https://securitylessons.com/guides/network-detection-and-response/ https://securitylessons.com/guides/network-detection-and-response/ Sun, 27 Sep 2026 00:00:00 GMT Flow records tell you what the network did. NDR is the layer that decides whether that behavior is normal — and raises an alarm when it is not. https://securitylessons.com/guides/scor-vs-concentration-exams/ https://securitylessons.com/guides/scor-vs-concentration-exams/ Mon, 21 Sep 2026 00:00:00 GMT SCOR is the map of the whole territory; a concentration is one region surveyed properly. Knowing which you are studying changes how you study it. https://securitylessons.com/guides/ise-engineer-career-path/ https://securitylessons.com/guides/ise-engineer-career-path/ Mon, 21 Sep 2026 00:00:00 GMT Identity work sits between the network and the business, which is why the job looks different from every other network security role. https://securitylessons.com/guides/how-long-to-pass-scor/ https://securitylessons.com/guides/how-long-to-pass-scor/ Mon, 21 Sep 2026 00:00:00 GMT There is no honest single number, but there is an honest way to work out yours — and it starts with the blueprint rather than the calendar. https://securitylessons.com/guides/firewall-engineer-to-security-architect/ https://securitylessons.com/guides/firewall-engineer-to-security-architect/ Mon, 21 Sep 2026 00:00:00 GMT The technical knowledge transfers almost entirely. What changes is who you are arguing with and what counts as a good answer. https://securitylessons.com/guides/failed-scor-350-701/ https://securitylessons.com/guides/failed-scor-350-701/ Mon, 21 Sep 2026 00:00:00 GMT The score report is more useful than it looks, and the tempting next move — studying harder rather than studying differently — is the one that wastes it. https://securitylessons.com/guides/cisco-security-vs-security-plus-cissp/ https://securitylessons.com/guides/cisco-security-vs-security-plus-cissp/ Mon, 21 Sep 2026 00:00:00 GMT They are not competing answers to the same question — they answer different questions, and choosing well means knowing which one you are actually asking. https://securitylessons.com/guides/ccnp-security-to-ccie/ https://securitylessons.com/guides/ccnp-security-to-ccie/ Mon, 21 Sep 2026 00:00:00 GMT The written exam is the one you have probably already passed. The lab is a different discipline, and pretending otherwise is why most attempts stall. https://securitylessons.com/guides/ccnp-security-study-plan/ https://securitylessons.com/guides/ccnp-security-study-plan/ Mon, 21 Sep 2026 00:00:00 GMT CCNP Security is two exams, and the order you take them in changes how hard the second one feels. https://securitylessons.com/guides/cisco-liveprotect/ https://securitylessons.com/guides/cisco-liveprotect/ Thu, 03 Sep 2026 00:00:00 GMT Live Protect puts validated eBPF policies — shields — into the kernel of a running switch, recording and, in enforce mode, blocking a disclosed vulnerability's exploit path while the fixed release is still in the change queue. https://securitylessons.com/guides/cisco-common-policy/ https://securitylessons.com/guides/cisco-common-policy/ Thu, 03 Sep 2026 00:00:00 GMT Common Policy makes Cisco ISE the exchange hub that normalizes user, device, and workload context into Security Group Tags, so campus, firewall, SD-WAN, and data-center domains all enforce against one consistent set of group classifications. https://securitylessons.com/guides/what-is-browser-isolation/ https://securitylessons.com/guides/what-is-browser-isolation/ Wed, 02 Sep 2026 00:00:00 GMT Browser isolation runs the risky part of browsing — executing a site's code — somewhere disposable, and sends the endpoint only a rendering of the result. https://securitylessons.com/guides/tetragon-ebpf-runtime-security/ https://securitylessons.com/guides/tetragon-ebpf-runtime-security/ Wed, 02 Sep 2026 00:00:00 GMT Tetragon turns the Linux kernel into a policy-aware security sensor — process-level visibility with Kubernetes context, and enforcement that can act in-kernel rather than after the fact. https://securitylessons.com/guides/soar-automation-basics/ https://securitylessons.com/guides/soar-automation-basics/ Wed, 02 Sep 2026 00:00:00 GMT SOAR turns the response half of security operations into software: playbooks that gather context in seconds and act within the permissions and approvals you configure. https://securitylessons.com/guides/security-home-lab-cml/ https://securitylessons.com/guides/security-home-lab-cml/ Wed, 02 Sep 2026 00:00:00 GMT Cisco Modeling Labs covers most of the topology work a security candidate needs — and knowing exactly where it stops tells you what to source elsewhere. https://securitylessons.com/guides/security-change-management/ https://securitylessons.com/guides/security-change-management/ Wed, 02 Sep 2026 00:00:00 GMT Security device changes fail in two directions at once — a bad rule can drop production traffic or silently open exposure — so the discipline is designing the way back before making the change. https://securitylessons.com/guides/sd-wan-security-basics/ https://securitylessons.com/guides/sd-wan-security-basics/ Wed, 02 Sep 2026 00:00:00 GMT SD-WAN replaces implicit trust in circuits with an authenticated, encrypted overlay — and, with direct internet access, moves a security perimeter to the branch edge. https://securitylessons.com/guides/identity-based-firewall-policy/ https://securitylessons.com/guides/identity-based-firewall-policy/ Wed, 02 Sep 2026 00:00:00 GMT An identity-based rule names a person or a group where an ordinary rule names an address — and the interesting engineering is in how the firewall learns which is which. https://securitylessons.com/guides/get-vpn-explained/ https://securitylessons.com/guides/get-vpn-explained/ Wed, 02 Sep 2026 00:00:00 GMT GET VPN encrypts traffic without building tunnels: a key server hands every site the group's keys, and the WAN keeps routing packets by the addresses they already carry. https://securitylessons.com/guides/ftd-clustering-vs-ha/ https://securitylessons.com/guides/ftd-clustering-vs-ha/ Wed, 02 Sep 2026 00:00:00 GMT Failover buys you a spare; clustering buys you a bigger firewall. The two answer different questions, and the blueprint expects you to know which question you are asking. https://securitylessons.com/guides/file-reputation-sandboxing/ https://securitylessons.com/guides/file-reputation-sandboxing/ Wed, 02 Sep 2026 00:00:00 GMT A file's verdict comes in stages: a hash lookup answers whether it is already known, a sandbox watches what it does, and retrospection keeps the case open. https://securitylessons.com/guides/encrypted-traffic-analysis/ https://securitylessons.com/guides/encrypted-traffic-analysis/ Wed, 02 Sep 2026 00:00:00 GMT Most traffic is encrypted and most of it will stay that way. Encrypted traffic analysis reads what encryption does not hide — handshakes, sizes, timing — and turns it into detection. https://securitylessons.com/guides/dmvpn-vs-flexvpn/ https://securitylessons.com/guides/dmvpn-vs-flexvpn/ Wed, 02 Sep 2026 00:00:00 GMT DMVPN is one topology model refined over two decades; FlexVPN is an IKEv2 framework that builds many topologies from the same parts. Which one fits depends on what else your VPN has to do. https://securitylessons.com/guides/dlp-fundamentals/ https://securitylessons.com/guides/dlp-fundamentals/ Wed, 02 Sep 2026 00:00:00 GMT DLP is the discipline of knowing which data matters, recognizing it wherever it moves, and enforcing policy at the points where it could leave — without grinding the business to a halt. https://securitylessons.com/guides/ccna-to-ccnp-security/ https://securitylessons.com/guides/ccna-to-ccnp-security/ Wed, 02 Sep 2026 00:00:00 GMT The distance from CCNA to CCNP Security is less about new commands and more about a new mental model — moving from making networks work to deciding what they should allow. https://securitylessons.com/guides/ccie-security-lab-preparation/ https://securitylessons.com/guides/ccie-security-lab-preparation/ Wed, 02 Sep 2026 00:00:00 GMT The lab is not a harder version of the qualifying exam — it is a different kind of test, and it rewards a different kind of preparation. https://securitylessons.com/guides/asa-to-ftd-migration/ https://securitylessons.com/guides/asa-to-ftd-migration/ Wed, 02 Sep 2026 00:00:00 GMT An ASA to FTD migration changes the operating model, not just the platform — plan it as a policy redesign with a conversion tool in the middle, not a copy job. https://securitylessons.com/guides/site-to-site-vpn-ftd/ https://securitylessons.com/guides/site-to-site-vpn-ftd/ Tue, 01 Sep 2026 00:00:00 GMT A site-to-site tunnel that comes up on the first deploy is the product of four decisions made in the right order — topology, IKE version, traffic selection, and NAT. https://securitylessons.com/guides/security-roles-by-certification-level/ https://securitylessons.com/guides/security-roles-by-certification-level/ Tue, 01 Sep 2026 00:00:00 GMT Certifications do not hand you a job title — they are associated with bands of responsibility, and knowing which band a credential commonly signals is how you aim your study at the role you actually want. https://securitylessons.com/guides/ransomware-kill-chain-network-controls/ https://securitylessons.com/guides/ransomware-kill-chain-network-controls/ Tue, 01 Sep 2026 00:00:00 GMT In most human-operated ransomware intrusions, encryption is a late step, not the first — and the earlier stages that touch the network give defenders repeated chances to detect and disrupt before impact. https://securitylessons.com/guides/network-syslog-best-practices/ https://securitylessons.com/guides/network-syslog-best-practices/ Tue, 01 Sep 2026 00:00:00 GMT Syslog is among the oldest telemetry you run and the first evidence you reach for — most of what makes it useful or useless is decided in device configuration, long before an incident. https://securitylessons.com/guides/ftd-tls-decryption/ https://securitylessons.com/guides/ftd-tls-decryption/ Tue, 01 Sep 2026 00:00:00 GMT Decryption buys your inspection engines a cleartext view of encrypted traffic — the question is where that visibility is worth its cost in throughput, complexity, and breakage. https://securitylessons.com/guides/ebpf-for-security-engineers/ https://securitylessons.com/guides/ebpf-for-security-engineers/ Tue, 01 Sep 2026 00:00:00 GMT eBPF lets verified programs run inside the Linux kernel at defined hook points — a security sensor at the layer every process sharing that kernel must cross for system calls. https://securitylessons.com/guides/duo-mfa-explained/ https://securitylessons.com/guides/duo-mfa-explained/ Tue, 01 Sep 2026 00:00:00 GMT Multifactor authentication defeats password-only replay; phishing-resistant authentication defeats the phishing relay that works around common second factors too. https://securitylessons.com/guides/ddos-protection-basics/ https://securitylessons.com/guides/ddos-protection-basics/ Tue, 01 Sep 2026 00:00:00 GMT DDoS defense is a placement problem: each attack class must be absorbed at the layer that has the capacity and the context to stop it. https://securitylessons.com/guides/workload-identity-primer/ https://securitylessons.com/guides/workload-identity-primer/ Mon, 31 Aug 2026 00:00:00 GMT A large share of the connections on a modern network have no human behind them — workload identity is how policy follows the software instead of the subnet. https://securitylessons.com/guides/why-segmentation-projects-fail/ https://securitylessons.com/guides/why-segmentation-projects-fail/ Mon, 31 Aug 2026 00:00:00 GMT The segmentation projects that fail usually break on unmapped traffic, not on enforcement technology — and the fix is sequencing, not products. https://securitylessons.com/guides/what-is-casb/ https://securitylessons.com/guides/what-is-casb/ Mon, 31 Aug 2026 00:00:00 GMT A CASB governs what happens inside cloud applications — tenant-level activity that network devices, without deep SaaS integration, see mostly as allowed connections to reputable domains. https://securitylessons.com/guides/swg-vs-firewall/ https://securitylessons.com/guides/swg-vs-firewall/ Mon, 31 Aug 2026 00:00:00 GMT A firewall governs what may cross a network boundary; a secure web gateway governs how users browse — the overlap in features hides a difference in anchor point. https://securitylessons.com/guides/security-concepts-cia-triad/ https://securitylessons.com/guides/security-concepts-cia-triad/ Mon, 31 Aug 2026 00:00:00 GMT Confidentiality, integrity, and availability are not a checklist — they are the three foundational failure modes of information security, and the vocabulary control decisions quietly use. https://securitylessons.com/guides/remote-access-vpn-vs-ztna/ https://securitylessons.com/guides/remote-access-vpn-vs-ztna/ Mon, 31 Aug 2026 00:00:00 GMT The working difference between remote access VPN and ZTNA is what a successful login typically buys: a routable network path, or brokered access to specific resources. https://securitylessons.com/guides/reading-packet-captures/ https://securitylessons.com/guides/reading-packet-captures/ Mon, 31 Aug 2026 00:00:00 GMT A packet capture answers exactly the question you bring to it — engineers who open one without a question just scroll. https://securitylessons.com/guides/post-mythos-security/ https://securitylessons.com/guides/post-mythos-security/ Mon, 31 Aug 2026 00:00:00 GMT Frontier AI models can now find software vulnerabilities — the defensive question is what to do as discovery gets cheaper and more parallel. https://securitylessons.com/guides/operationalizing-ai-soc/ https://securitylessons.com/guides/operationalizing-ai-soc/ Mon, 31 Aug 2026 00:00:00 GMT The distance between an AI that drafts your query and an AI that acts on your alerts is an operational discipline, not a product upgrade. https://securitylessons.com/guides/machine-learning-ips/ https://securitylessons.com/guides/machine-learning-ips/ Mon, 31 Aug 2026 00:00:00 GMT Signatures catch what someone has already described; models generalize from examples — a modern IPS can run both, and knowing which is doing the work changes how you tune and triage it. https://securitylessons.com/guides/lateral-movement-defense/ https://securitylessons.com/guides/lateral-movement-defense/ Mon, 31 Aug 2026 00:00:00 GMT The intrusion you eventually read about was rarely the initial foothold — it was everything the attacker reached from there. https://securitylessons.com/guides/ise-guest-access/ https://securitylessons.com/guides/ise-guest-access/ Mon, 31 Aug 2026 00:00:00 GMT ISE guest access built on central web authentication is one flow — MAB, redirect, portal, CoA — dressed in three portal patterns; understand the flow once and each design becomes a variation. https://securitylessons.com/guides/ise-byod-onboarding/ https://securitylessons.com/guides/ise-byod-onboarding/ Mon, 31 Aug 2026 00:00:00 GMT BYOD onboarding turns an unknown personal device into a known, certificate-bearing one — and it can be completed without an IT technician ever touching the device. https://securitylessons.com/guides/fmc-access-control-policy-design/ https://securitylessons.com/guides/fmc-access-control-policy-design/ Mon, 31 Aug 2026 00:00:00 GMT An access control policy is read top to bottom, first match wins — good design is deciding what each rule can see and when it gets to see it. https://securitylessons.com/guides/cryptography-for-network-engineers/ https://securitylessons.com/guides/cryptography-for-network-engineers/ Mon, 31 Aug 2026 00:00:00 GMT Network security runs on a small set of cryptographic primitives used over and over — learn the five jobs they do and the protocols you configure become rearrangements of familiar parts. https://securitylessons.com/guides/ai-accelerated-attacks/ https://securitylessons.com/guides/ai-accelerated-attacks/ Mon, 31 Aug 2026 00:00:00 GMT AI has not given attackers new categories of attack so much as it has driven down the cost, skill, and time that used to limit the old ones. https://securitylessons.com/guides/zero-trust-for-ai-agents/ https://securitylessons.com/guides/zero-trust-for-ai-agents/ Sun, 30 Aug 2026 00:00:00 GMT An AI agent is a workload with an identity and credentials — and zero trust already tells you how to treat one of those: no implicit trust, least privilege, and a policy decision the agent does not make itself. https://securitylessons.com/guides/what-is-agentic-ai-security/ https://securitylessons.com/guides/what-is-agentic-ai-security/ Sun, 30 Aug 2026 00:00:00 GMT An agent is software delegated a goal and the autonomy to act — today usually a language model given tools and credentials — making it both a new SOC workforce and a new population of identities to govern. https://securitylessons.com/guides/spf-dkim-dmarc-explained/ https://securitylessons.com/guides/spf-dkim-dmarc-explained/ Sun, 30 Aug 2026 00:00:00 GMT Email's base protocol never authenticated a sender — SPF bolts on an IP authorization check, DKIM a cryptographic signature, and DMARC ties either one to the address the reader actually sees. https://securitylessons.com/guides/siem-vs-xdr/ https://securitylessons.com/guides/siem-vs-xdr/ Sun, 30 Aug 2026 00:00:00 GMT A SIEM is at heart a data platform you feed and tune; XDR is at heart a detection product built on an integrated sensor set — different jobs, and many SOCs run both. https://securitylessons.com/guides/shadow-ai-visibility/ https://securitylessons.com/guides/shadow-ai-visibility/ Sun, 30 Aug 2026 00:00:00 GMT Employees adopted AI tools faster than any approval process could follow. The network is where that adoption becomes visible, and where it can be governed without pretending it away. https://securitylessons.com/guides/securing-ai-infrastructure/ https://securitylessons.com/guides/securing-ai-infrastructure/ Sun, 30 Aug 2026 00:00:00 GMT An AI deployment is a stack of ordinary infrastructure — data stores, clusters, artifact registries, APIs — and it is secured with network controls engineers already know, applied to assets they may not have mapped yet. https://securitylessons.com/guides/securing-agent-protocols/ https://securitylessons.com/guides/securing-agent-protocols/ Sun, 30 Aug 2026 00:00:00 GMT Agent protocols like MCP and A2A ride deliberately ordinary plumbing — the new risk is not the wire format but that protocol content becomes model input and endpoints hold real authority. https://securitylessons.com/guides/quantum-safe-hardware-trust/ https://securitylessons.com/guides/quantum-safe-hardware-trust/ Sun, 30 Aug 2026 00:00:00 GMT A signature a device checks at boot may need to stay unforgeable for years of hardware life — which is why signing infrastructure moves early in the quantum-safe signature migration. https://securitylessons.com/guides/qkd-vs-pqc/ https://securitylessons.com/guides/qkd-vs-pqc/ Sun, 30 Aug 2026 00:00:00 GMT Quantum key distribution and post-quantum cryptography both promise protection from a quantum adversary, but they solve the problem in completely different layers of the stack. https://securitylessons.com/guides/post-quantum-cryptography-explained/ https://securitylessons.com/guides/post-quantum-cryptography-explained/ Sun, 30 Aug 2026 00:00:00 GMT The algorithms taking over the work RSA and elliptic curves do today are already standardized — what changes for a network engineer is the handshake, the byte counts, and the migration order. https://securitylessons.com/guides/pki-explained/ https://securitylessons.com/guides/pki-explained/ Sun, 30 Aug 2026 00:00:00 GMT A certificate is a signed claim that a public key belongs to a subject — a name or other identifier — and PKI is the machinery that makes such claims checkable at scale. https://securitylessons.com/guides/operationalizing-pqc/ https://securitylessons.com/guides/operationalizing-pqc/ Sun, 30 Aug 2026 00:00:00 GMT NIST's first post-quantum standards are final; what remains is a migration program — inventory, hybrid key exchange, handshake engineering, and signatures on their own clock. https://securitylessons.com/guides/llm-security-primer/ https://securitylessons.com/guides/llm-security-primer/ Sun, 30 Aug 2026 00:00:00 GMT Prompt injection exists because a language model reads trusted instructions and untrusted content in the same context — a trust boundary that structure can shape but no general-purpose mechanism yet makes enforceable by construction. https://securitylessons.com/guides/ise-profiling-deep-dive/ https://securitylessons.com/guides/ise-profiling-deep-dive/ Sun, 30 Aug 2026 00:00:00 GMT ISE profiling classifies endpoints by accumulating evidence from probes until a profiling policy's certainty threshold is met — classification that policy can act on, but never authentication. https://securitylessons.com/guides/ise-posture-assessment/ https://securitylessons.com/guides/ise-posture-assessment/ Sun, 30 Aug 2026 00:00:00 GMT Authentication establishes who is connecting; posture assessment checks whether the device itself meets health policy — and ISE turns the difference into access. https://securitylessons.com/guides/ise-deployment-personas/ https://securitylessons.com/guides/ise-deployment-personas/ Sun, 30 Aug 2026 00:00:00 GMT An ISE persona is a role a node runs — administration, monitoring, or policy service — and deployment design is deciding which nodes run which roles. https://securitylessons.com/guides/ipsec-vs-ssl-vpn/ https://securitylessons.com/guides/ipsec-vs-ssl-vpn/ Sun, 30 Aug 2026 00:00:00 GMT The two VPN families differ less in strength than in where they live: IPsec is a network-layer suite whose ESP data plane is its own IP protocol, while SSL VPN rides TLS on the port networks most reliably permit. https://securitylessons.com/guides/harvest-now-decrypt-later/ https://securitylessons.com/guides/harvest-now-decrypt-later/ Sun, 30 Aug 2026 00:00:00 GMT No quantum computer known today can break your VPN — and that fact protects nothing that was recorded today and can be decrypted the day one can. https://securitylessons.com/guides/ftd-prefilter-policy/ https://securitylessons.com/guides/ftd-prefilter-policy/ Sun, 30 Aug 2026 00:00:00 GMT The prefilter policy is the first phase of access control on a Secure Firewall, and its most powerful action is the one that says: nothing further needs to look at this flow. https://securitylessons.com/guides/ftd-nat-order-of-operations/ https://securitylessons.com/guides/ftd-nat-order-of-operations/ Sun, 30 Aug 2026 00:00:00 GMT Secure Firewall evaluates NAT rules in three fixed sections with first-match-wins semantics — once you can predict which rule a packet hits, most NAT surprises disappear. https://securitylessons.com/guides/ftd-high-availability/ https://securitylessons.com/guides/ftd-high-availability/ Sun, 30 Aug 2026 00:00:00 GMT A failover pair earns its keep in one moment — the failure — and whether that moment is boring depends entirely on decisions made at design time. https://securitylessons.com/guides/eap-tls-explained/ https://securitylessons.com/guides/eap-tls-explained/ Sun, 30 Aug 2026 00:00:00 GMT EAP-TLS is the most direct 802.1X method for having both sides prove themselves with a certificate — which makes it one of the strongest commonly deployed methods — and the one that fails on lifecycle details. https://securitylessons.com/guides/device-trust-explained/ https://securitylessons.com/guides/device-trust-explained/ Sun, 30 Aug 2026 00:00:00 GMT Zero-trust access evaluates the machine as well as the user — device identity, management state, and health become access conditions that policy can keep re-checking, not a one-time gate. https://securitylessons.com/guides/crypto-agility/ https://securitylessons.com/guides/crypto-agility/ Sun, 30 Aug 2026 00:00:00 GMT Crypto-agility is the ability to change algorithms, parameters, and keys without redesigning the systems that use them — and the post-quantum migration is its broadest test yet. https://securitylessons.com/guides/cisco-talos-explained/ https://securitylessons.com/guides/cisco-talos-explained/ Sun, 30 Aug 2026 00:00:00 GMT Talos is Cisco's threat intelligence and research organization — and a major source of what a properly licensed, configured, and updating firewall knows, before you enumerate a single indicator, about which addresses, domains, and files to distrust. https://securitylessons.com/guides/ai-powered-threat-hunting/ https://securitylessons.com/guides/ai-powered-threat-hunting/ Sun, 30 Aug 2026 00:00:00 GMT AI compresses the slow parts of a hunt — forming hypotheses, querying telemetry, summarizing results — while high-impact conclusions and disruptive actions stay under risk-based human review. https://securitylessons.com/guides/ai-in-the-soc-for-network-engineers/ https://securitylessons.com/guides/ai-in-the-soc-for-network-engineers/ Sun, 30 Aug 2026 00:00:00 GMT Machine learning has been quietly grading your alerts for years. What changes now is how much of the triage loop runs without a human in it — and how much that depends on telemetry you own. https://securitylessons.com/guides/what-is-zero-trust-network-access/ https://securitylessons.com/guides/what-is-zero-trust-network-access/ Sat, 29 Aug 2026 00:00:00 GMT Behind the slogan is a written-down architecture: a policy decision point, enforcement points in the path to every protected resource, and access authorized per session by identity, device posture, and context rather than granted by network location. https://securitylessons.com/guides/what-is-umbrella-dns-security/ https://securitylessons.com/guides/what-is-umbrella-dns-security/ Sat, 29 Aug 2026 00:00:00 GMT Reaching a named destination on the internet depends on DNS resolution. Umbrella turns that step into a policy decision — here is the mechanism, and why it punches above its weight. https://securitylessons.com/guides/what-is-snort/ https://securitylessons.com/guides/what-is-snort/ Sat, 29 Aug 2026 00:00:00 GMT The open-source intrusion prevention engine that became the inspection heart of Cisco Secure Firewall Threat Defense — how the engine works, what Snort 3 changed, and where rule literacy pays. https://securitylessons.com/guides/what-is-cisco-ise/ https://securitylessons.com/guides/what-is-cisco-ise/ Sat, 29 Aug 2026 00:00:00 GMT Identity Services Engine is the policy decision point of a Cisco network — the system that decides who and what gets access, to how much, and in what state, while switches and controllers enforce the answer. https://securitylessons.com/guides/what-is-802-1x/ https://securitylessons.com/guides/what-is-802-1x/ Sat, 29 Aug 2026 00:00:00 GMT The protocol that decides whether a device gets on your network at all — how 802.1X actually works, where MAB fits, and why enterprise interviews keep asking about it. https://securitylessons.com/guides/trustsec-microsegmentation/ https://securitylessons.com/guides/trustsec-microsegmentation/ Sat, 29 Aug 2026 00:00:00 GMT East-west traffic is where intrusions spread — and where IP-based ACLs strain under their own weight. TrustSec writes policy in groups instead of addresses, and segmentation becomes something humans can read. https://securitylessons.com/guides/tacacs-vs-radius/ https://securitylessons.com/guides/tacacs-vs-radius/ Sat, 29 Aug 2026 00:00:00 GMT One secures who gets on the network; the other secures who gets to change it. The classic comparison every network engineer is asked — settled properly. https://securitylessons.com/guides/sase-vs-sse/ https://securitylessons.com/guides/sase-vs-sse/ Sat, 29 Aug 2026 00:00:00 GMT Two overlapping acronyms describe where enterprise security is converging. The distinction is simple once stated — and knowing it precisely is table stakes in modern design conversations. https://securitylessons.com/guides/quantum-safe-vpn/ https://securitylessons.com/guides/quantum-safe-vpn/ Sat, 29 Aug 2026 00:00:00 GMT The keys protecting conventional tunnels rest on math a future quantum computer breaks. Here is how the fix lands in IKEv2 and TLS, at tunnel level — standards, sizes, sequence. https://securitylessons.com/guides/netflow-and-network-telemetry/ https://securitylessons.com/guides/netflow-and-network-telemetry/ Sat, 29 Aug 2026 00:00:00 GMT You cannot secure what you cannot see. Flow records and telemetry turn the network itself into a sensor — the visibility layer network detection stands on. https://securitylessons.com/guides/ikev1-vs-ikev2/ https://securitylessons.com/guides/ikev1-vs-ikev2/ Sat, 29 Aug 2026 00:00:00 GMT Nearly every IPsec tunnel starts with an IKE negotiation — and the difference between version 1 and version 2 shows up in reliability, security, and how often you get paged. https://securitylessons.com/guides/asa-vs-ftd/ https://securitylessons.com/guides/asa-vs-ftd/ Sat, 29 Aug 2026 00:00:00 GMT The firewall that ran the enterprise for twenty years versus the platform that replaced it — what carried over, what is new, and where your study time pays.